1. Field of the Invention
The present invention relates to a method for regulating an excited oscillation of a system to a resonance case of the system.
2. Description of Related Art
To excite oscillatory systems and to regulate them to a resonance case of the system, it is necessary to record the excited oscillations of the system. If digital techniques are used for this purpose, the oscillations are sampled in a discrete process. In order to counteract errors made during sampling, a sampling frequency is used that is substantially greater than the maximum frequency, in particular, greater than double the maximum frequency of the excited system. This approach is considered to be an application of the Nyquist theorem. It prevents oscillations from being sampled too slowly, whereby an effect can occur, which, when evaluated, suggests that an oscillation having a substantially lower frequency has been recorded, although this is not the case. This is generally referred to as aliasing. In particular, it is not possible in such cases to ascertain the actual frequency and phase relation of the sampled oscillation. The inherent drawback is that a constantly very high sampling frequency must be used, thereby resulting in substantial computational outlay for a recording device that is used. This substantial computational outlay is reflected in a high demand for chip surface area when the recording device is realized as an integrated circuit, and in a substantial power consumption.
Regulating systems which employ the method can be used, in particular, for systems such as ESP (electronic stability program), ROM (roll-over mitigation), EAS (electronic active steering), ASC (active suspension control), SbW (steer by wire) and other vehicle stability applications. This is due to the fact that what are generally referred to as inertia sensors are used as rotation-rate sensors. These typically have at least one part, a component, that is set into oscillation in response to excitation and that produces a Coriolis effect in response to a rotation of the sensor. This allows a relative movement to be measured between the oscillating portion and the remaining rotation-rate sensor. Other fields of applications of such sensors include NC applications, such as navigation, man-machine interfaces, game consoles, and sport and medical fields. These sensors must meet stringent requirements, in particular, in terms of a substantial computing capacity, a high level of stability, a minimal chip surface area and a low power consumption.
There is a need for a method which will reduce the computational outlay required for such a device and, in particular, thereby minimize the demand for chip surface area and reduce power consumption as well.